Double throw switch



Nov. 29, 1932 H. J. HAMMERLY DOUBLE THROW SWITCH Filed April 18, 1931 Patented Nov. 29, 1932 UNITED STATES PATENT OFFICE HERMAN J. HAMMERLY, OF WALLINGFORD, CONNECTICUT, ASSIGNOR TO THE TRUMBULL ELECTRIC MANUFACTURING COMPANY, OF PLAINVILLE, CONNECTICUT, A CORPORA- TION OF CONNECTICUT DOUBLE THROW SWITCH Application filed April 18,

My invention relates to double-throw enclosed switches and particularly to a means for locking the switching members in either of the on positions or in the intermediate off position.

One object of my invention is to provide a simple and inexpensive device which can be readily applied to a standard type box to facilitate locking of the movable switch member in the desired position.

Another object is to provide locking mechanism which can be applied to the usual type of double-throw switch, such for instance as shown in the Getchell Patent 1,483,846. It is immaterial, however, whether the switch is of the quick make-and-break type or of the slow moving contact type.

In one simple form the invention contemplates the provision of a spring actuated latch member pivoted to one wall of the box and coacting with the recessed hub of the operating handle. As a convenient means of installation this latch is mounted upon a bracket which serves as a stationary element of the locking means. This latch is provided with a projection and the hub of the handle is provided. with three recesses or notches coacting with the projection of the latch in the off position andin both of the on positions.

Fig. 1 isa perspective view of a switch embodying the improvements of my invention, the cover being open and broken away and the parts of the switch being in the off position' Fig. 2 is a longitudinal section and plan showing the parts of the locking attachment.

Fig. 3 is a fragmentary side view showing the latching member and its support adjacent the hub of the operating handle.

Fig. 4 is an end view of the hub and the operating handle.

The box 5 and cover 6 may beof a suitable type and provided with the usual spring latch.

The movable switch members are in the form of two armed blades 7 hinged to posts 8 and adapted to coact respectively with the interior contacts 9 and 10.

The invention is applicable to the control 1931. Serial No. 531,057.

of any number of circuits and for convenience I have illustrated two of the blades 7 connected by an insulating cross-bar 11.

The operating crank 12 has one end fitted in a hole 13, in one wall of the box, and the other end 14 supported in a hub 15 of a handle 16, this hub being in its turn supported in a wall of the box, the intermediate portion engaging the U-shaped bracket 11.

The handle member is provided with a series of recesses or notches 17, 18 and 19 which may be formed in an integral portion of the handle or in a ring connected to the hub, for instance by rivets 20, so that in fact these notches are in a part ofthe hub of the operating handle.

A latch member 21 is pivoted to the stud 22, which is carried by a bracket 23. This bracket in turn is secured to a wall of the box in any suitable manner.. The latch member is provided with a projection or lug 24 which is adapted to fit in any one of the recesses 17, 18 or 19, depending upon the position of the handle. A spring 25 supported on the stud 22, has one end engaging the abutment 26 on the bracket and the other end engaging the latch member 21 to press the latch member toward the hub of the operating handle. The shape of the recesses and the projecting lug 24 is such that the latch normally provides a mere frictional resistance to the rotation of the operating handle.

For the purpose of locking the switch the latch member is provided with an arm 27 adapted to travel adjacent the arm 28 of the bracket 23, and these arms are provided with openings 29 for the insertion of the hasp of a padlock or other sealing or locking means.

When the arm 27 is held stationary it is impossible to turn the operating handle because of the presence of the lug 24 in one of the. notches 17, 18 or 19. l-Vhen the arm 27 is free there is nothing to obstruct the movement of the operating handle 16 and the actuation of the movable switch member in the usual way.

The spring pressure of the lug 24 into the recesses or notches 17, 18 or 19 in the hub of the handle retains the handle and the movable switch blades in position in opposition to vibration, gravity or other tendency to move away from the set position and. this feature is of course very useful when the operating parts are not locked or sealed in a definite position.

I claim:

1. A double-throw switch including a box,

I a'switch within said box, an external operat ing handle having operable connection with said switch and having a number of angular sided lug-receiving recesses corresponding with the usual central off position and the two respective on positions of the switch, a bracket mounted outside of said box and having a lock-receiving slot, a pivoted latch member. mounted outside of said box and having an angular sided lug for engagement with any one of the recesses in said handle, said latch alsohaving a projecting portion provided with a lock-receiving slot arranged to'register with the slot in said bracket when the lug on said latch is engaged in one of the recesses on said handle.

2. A multi-position switch construction including a box, a switch within said box, an external handle having operable connection with said switch and having a number of angular sided latch receiving recesses corresponding-with the usual central ofl' position and the two respective on positions of the switch, a bracket mounted outside of said box and having a lock-receiving slot, and a latch member mounted outside of said box and having an angular sided lug for engagement with any one of the recesses on said handle, said latch also having a lock-receiving slot positioned to register with the slot in said bracket, when the lug on said latch is engaged in any one of the recesses in said external operating handle.

3. A multi-position switch construction including a. box, a switch within said box, an external handle having operable connection with said switch and having a number of angular sided latch receiving recesses, a bracket mounted outside of said box and havmg a lock-receiving slot, a latch member mounted outside of said box and having an angular sided lug for engagement with any one of the recesses on said handle. said latch also having a lock-receiving slot of positioned to register with the slot in said bracket when the lug on said latch is engaged in any one of the recesses in said external operating handle, and a spring for urging said latch member into fully latched position, the recesses in said handle and the lug on said latch having an angular engagement with respect to each other whereby the said handle may be moved for normal operation of the switch without manual operation of said'latch when said latch is not locked to prevent the movement of said handle.

4. A double throw switch construction ineluding a box containing the switch mechanism, an operating handle member pivotally supported by the side of the box and having a handle projecting forwardly from the box, a latch member hinged to the side of the box to swing parallel to the side of the box in rear of the handle, one of said members having three recesses and the other member having a cooperating projection adapted to frictionally hold the handle in the usual central ofi position and in either of the usual on positions of the switch, said latch member and said box having pertinent projections for the attachment of a locking device to aiiord means for positively locking the latch to prevent the movement of the handle, and a spring for normally pressing the latch toward the handle but permitting the handle to operate when the latch is not positively locked.

5. An enclosed inulti-position switch con? struction including a box, a movable switch element within the box, an external handle member mounted at one side of the box to swing in a plane substantially parallel with the side of the box and having an operable connection with the movable switch element within the box, a latch member carried by the outside of the box and movable in a plane substantially parallel with the side of the box, a spring for pressing the latch member toward the handle member, one of said members having a plurality of recesses and the other member having a cooperating projecting lug adapted to frictionally engage in any one of the recesses, the walls of the recesses and the engaging edge of the lug being cam shaped to permit the normal operating movement of the handlev member when the latch member is free to move, said latch member and said box having pertinent projections adapted to receive a locking device so that when the lug is in one of the recesses the latch member-may be locked against movement and thus prevent movement of the handle member when the latch member is locked.

HERMAN J. HAMMERLY. 

